The covalent attachment to deoxyribonucleic acid in vivo of a large number of different types of chemical compounds (both normal cellular constitutents such as proteins and amino acids, and also exogenous compounds such as drugs, carcinogens, etc.) have been shown to exert profound effects upon cells. Four independent research activities relate to this problem of DNA adducts--(1) normal covalent attachment of DNA to membranes, chromosomal linkers, etc.; (2) the role of radiation enhanced adduct formation to DNA in cell killing and mutagenesis; (3) the relevance to DNA adducts to the cross-linking theory of cell aging; and (4) the relevance of DNA adducts to chemical and radiation-induced carcinogenesis. Since many of the known radiation-induced adducts to DNA appear to be mediated by radical reactions whether X-radiation or UV radiation is used, this conference also offers a unique common ground for a useful dialogue between radiation chemists and photochemists. The proposed conference on the chemistry and biological consequences of DNA adducts would be the first on this important subject and would represent an attempt to integrate the diverse fields of radiation biology, molecular biology of aging and carcinogenesis.